HADOOP-16870. Use spotbugs-maven-plugin instead of findbugs-maven-plugin (#2753)

Removed findbugs from the hadoop build images and added spotbugs instead.
Upgraded SpotBugs to 4.2.2 and spotbugs-maven-plugin to 4.2.0.

Reviewed-by: Masatake Iwasaki <iwasakims@apache.org>
33 files changed